Chronic pain is a prevalent, costly, and medically challenging problem. Chronic low back and neck pain represent the most prevalent disorders of the many chronic pain diagnoses. Emerging data suggests that chronic low back and neck pain, considered chronic regional spinal pains (CRSP), can lead to a process of central sensitization whereby ongoing painful input is associated with alterations in the peripheral and central nervous system processing. In some individuals, the process of central sensitization can lead to a transition from regional pain located in the low back or neck to widespread pain, similar to fibromyalgia (FM). In fact, there is now a persuasive body of experimental evidence demonstrating that central sensitization is a characteristic feature of pain in FM. Despite this demonstration of shared pathophysiology, few researchers have investigated the clinical factors that are postulated to drive the transition from CRSP to FM. Identification of these risk factors is important, as it has been demonstrated that individuals experiencing FM have a higher rate of disability and decreased quality of life as compared to individuals with CRSP, representing a worsening clinical picture. The purpose of this study is to identify the clinical characteristics in persons with CRSP that can predict their transition to FM. This study is innovative in that it will be the first to our knowledge to examine this transition to FM specifically in two groups with chronic regional spinal pain. This study is feasible in scope as it will utilize Kaiser Permanente's large, well-maintained clinical database managed in part by Dr. Perrin, co-sponsor and director of the Kaiser Permanente Center for Health Research. Additionally, Dr. Jones has extensive clinical expertise and National Institute of Health funding in FM. The first aim of this proposed study is to test the central sensitization theory in CRSP by determining if individuals with a history of CRSP more frequently transition to FM as compared to individuals with a history of a chronic pain disorder not prone to central sensitization, particularly postherpetic and diabetic neuropathy. The second aim is to identify the risk factors for the transition to FM and generate a model that predicts this transition. The final aim will be to evaluate whether the effect of the predictor variables on the transition to FM depends on type of pain. The proposed study will uncover new knowledge that can explain and predict high risk groups for the transition to FM. It is estimated that the economic burden of FM in the United States is at least 20 billion dollars in annual direct costs alone. Identifying these groups and intervening will not only slow an expanding economic burden but will also prevent further disability, allowing these individuals to remain involved in their lives and society at large. [unreadable] [unreadable] [unreadable]